---
name: "ctags-json-output"
section: "5"
platform: "linux"
package: "ctags"
version: "1:6.2.1-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/ctags-json-output"
---

# ctags-json-output(5)

JSON based ctags output

## Name

ctags-json-output - JSON based ctags output

## SYNOPSIS

```
ctags --output-format=json ...
```

## DESCRIPTION

Universal Ctags supports JSON \<https://www.json.org/\> (strictly speaking JSON Lines \<https://jsonlines.org/\>) output format if the ctags executable is built with **libjansson**.  JSON output goes to standard output by default.

## FORMAT

Each JSON line represents a tag.

```
$ ctags --extras=+p --output-format=json --fields=-s input.py
{"_type": "ptag", "name": "JSON_OUTPUT_VERSION", "path": "1.0", "pattern": "in development"}
{"_type": "ptag", "name": "TAG_FILE_SORTED", "path": "1", "pattern": "0=unsorted, 1=sorted, 2=foldcase"}
...
{"_type": "tag", "name": "Klass", "path": "/tmp/input.py", "pattern": "/^class Klass:$/", "language": "Python", "kind": "class"}
{"_type": "tag", "name": "method", "path": "/tmp/input.py", "pattern": "/^    def method(self):$/", "language": "Python", "kind": "member", "scope": "Klass", "scopeKind": "class"}
...
```

A key not starting with **\_** is mapped to a field of ctags. "**--output-format=json --list-fields**" options list the fields.

A key starting with **\_** represents meta information of the JSON line.  Currently only **\_type** key is used. If the value for the key is **tag**, the JSON line represents a regular tag. If the value is **ptag**, the line represents a pseudo-tag.

The output format can be changed in the future. **JSON\_OUTPUT\_VERSION** pseudo-tag provides a change client-tools to handle the changes.  Current version is "1.0". A client-tool can extract the version with **path** key from the pseudo-tag.

The JSON output format is newly designed and has no limitation found in the default tags file format.

- •

  The values for **kind** key are represented in long-name flags. No one-letter is here.

- •

  Scope names and scope kinds have distinguished keys: **scope** and **scopeKind**. They are combined in the default tags file format.

## DATA TYPE USED IN A FIELD

Values for the most of all keys are represented in JSON string type. However, some of them are represented in string, integer, and/or boolean type.

"**--output-format=json --list-fields**" options show What kind of data type used in a field of JSON.

```
$ ctags --output-format=json --list-fields
#LETTER NAME           ENABLED LANGUAGE         JSTYPE FIXED DESCRIPTION
F       input          yes     NONE             s--    no    input file
...
P       pattern        yes     NONE             s-b    no    pattern
...
f       file           yes     NONE             --b    no    File-restricted scoping
...
e       end            no      NONE             -i-    no    end lines of various items
...
```

**JSTYPE** column shows the data types.

- **'s'**

  string

- **'i'**

  integer

- **'b'**

  boolean (true or false)

For an example, the value for **pattern** field of ctags takes a string or a boolean value.

## VERSIONS

### Change since "0.0"

- •

  New key **kindName** for **TAG\_ROLE\_DESCRIPTION** pseudo tag

  **kindName** is added to store the name of the kind in **TAG\_ROLE\_DESCRIPTION** pseudo tags.

  In 0.0, a "TAG\_ROLE\_DESCRIPTION" pseudo tag was printed like:

  ```
  {"_type": "ptag", "name": "TAG_ROLE_DESCRIPTION",
                    "parserName": "LANG!KIND", }
  ```

  In 1.0, it is printed like:

  ```
  {"_type": "ptag", "name": "TAG_ROLE_DESCRIPTION",
                    "parserName": "LANG",
                    "kindName": "KIND",  }
  ```

## SEE ALSO

[ctags(1)](/ctags/1.md), [tags(5)](/tags/5.md), [ctags-client-tools(7)](/ctags-client-tools/7.md)